Abstract:This paper proposes the fault diagnosis and fault-tolerant control (FTC) for reentry hypersonic vehicles with external disturbance/interior white noise composite interference and intermittent faults. First, the reentry attitude system model and the intermittent failure model are given. Then, based on the random fixed-amplitude failure mode, the periodic external disturbance in the angular rate system is pre-processed. Due to the existence of white noise in the system, two hypothesis tests are proposed based on the noise distribution characteristics and the improved residual signal, and then two threshold intervals for detecting faults are designed to detect the occurrence and disappearance time of intermittent faults. Compared with the traditional residual design method, the improved residual detection is more accurate. Based on the expanded system, an adaptive estimation law is designed to estimate the faults and make the estimation error satisfy $L_2$-gain interference suppression. Finally, an adaptive FTC algorithm is proposed to make the system's angle output track a given reference signal. Lyapunov functions prove the stability of the proposed method, and Matlab simulation verifies its effectiveness.